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                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                   SCHEDULE TO
                             TENDER OFFER STATEMENT
          Under Section 14(d)(1) of the Securities Exchange Act of 1934


                                (Amendment No. 4)
                                ----------------
                               Ansaldo Signal N.V.
                            (Name of Subject Company)

                            Ansaldo Trasporti S.p.A.
                             (Name of Filing Person)

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                 Common Shares, Nominal Value NLG .01 per share
                         (Title of Class of Securities)

                                ----------------
                                   NO5515 10 6
                      (CUSIP Number of Class of Securities)

                                ----------------
                                 Dr. Luigi Roth
                             Chief Executive Officer
                            Ansaldo Trasporti S.p.A.
                           Via Nuova delle Brecce 260
                               80147 Naples, Italy
                        Telephone: 011 (39) 081-243-2215
                        Facsimile: 011 (39) 081-243-2710
           (Name, Address and Telephone Number of Person authorized to
         Receive Notices and Communications on Behalf of Filing Person)


                            CALCULATION OF FILING FEE
        Transaction Valuation $15,136,875   Amount of Filing Fee $3,027.38

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[ X ]    Check box if any part of the fee is offset as provided by Rule 0-11
         (a)(2) and identify the filing with which the offsetting fee was
         previously paid. Identify the previous filing by registration statement
         number, or the Form or Schedule and the date of its filing.

Amount Previously Paid: $3,027.38
Form or Registration No.: Amendment No. 2 to Schedule TO
Filing Party: Ansaldo Trasporti S.p.A.
Date Filed: February 18, 2000

[ ] Check the box if the filing relates solely to preliminary communications
made before the commencement of a tender offer.

Check the appropriate boxes below to designate any transactions to which the
statement relates:

[ X ] third party tender offer subject to Rule 14d-1.
[   ] issuer tender offer subject to Rule 13e-4.
[ X ] going private transaction subject to Rule 13e-3.
[   ] amendment to Schedule 13D under Rule 13d-2.

Check the following box if the filing is a final amendment reporting the results
of the tender offer:

[   ]

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         This Amendment No. 4 to Tender Offer Statement on Schedule TO relates
to the offer by Ansaldo Trasporti S.p.A., an Italian corporation (the
"Purchaser"), to purchase all of the outstanding common shares, nominal value
NLG .01 per share, of Ansaldo Signal N.V., a corporation organized under the
laws of The Netherlands, at $4.05 per Common Share, net to the seller in cash,
without interest, upon the terms and subject to the conditions set forth in the
Offer to Purchase, dated February 18, 2000, a copy of which was filed with the
Securities and Exchange Commission as Exhibit (a)(1) to Amendment No. 2 to
Schedule TO on February 18, 2000 (the "Offer to Purchase").

ITEM 8.  Interest in Securities of the Subject Company.

         The disclosure contained in the Offer to Purchase relating to Item 8 of
Schedule TO and Item 11 of Schedule 13E-3 is hereby amended and supplemented by
the information set forth in the press release, dated March 21, 2000, of the
Purchaser, a copy of which is attached hereto as Exhibit (a)(9) and incorporated
herein by reference.

ITEM 12. Materials to be Filed as Exhibits.

(a)(9) Press Release of Purchaser, dated March 21, 2000.




                                    SIGNATURE


         After due inquiry and to the best of my knowledge and belief, I certify
that the information set forth in this statement is true, complete and correct.


Date:    March 21, 2000

                                                 ANSALDO TRASPORTI S.p.A.




                                                 By:    /s/ Dott. Luigi Roth
                                                    ----------------------------
                                                    Name:   Dott. Luigi Roth
                                                    Title:  Chief Executive
                                                            Officer


         After due inquiry and to the best of my knowledge and belief, I certify
that the information required by Schedule 13E-3 with respect to the subject
company that is set forth in this statement is true, complete and correct.


Date:    March 21, 2000



                                                 ANSALDO SIGNAL N.V.




                                                 By:    /s/ James N. Sanders
                                                    ----------------------------
                                                    Name:   James N. Sanders
                                                    Title:  Chief Executive
                                                            Officer